Film printing apparatus



April 29, 1- A. w. TO-NDREAU 2,240,083

FILM PRINTING APPARATUS Filed Jan. 9, 1939 5 Sheets-Sheet l 1N VENTOR. ALBERT 14 END EAU- ATTORNEY.

April 29, 1941. A. w. TONDREAU 2,240,083

FILM PRINTING APPARATUS Filed Jan. 9, 1939 5 Sheets-Sheet 2 o p 4 i o 1 Q, I

' 16/ 9 A28 44 fi/ [42 m fiat/)1 F1512- /8 war a INVENTOR. ALBERT W 7b/v0eEAu ATTORNEY.

April 29, 1941.

A. W. TONDREAU FILM PRINTING APPARATUS Filed Jan. 9, 1939 5 Sheets-Sheet 3 FIE-LE- 1N VENTOR. ALBEQT W ToA/DPEAU ATTORNEY.

April 29, 1941- A. w. TONDREAU 2,240,083

FILM PRINTING APPARATUS" Fil ed Jan. 9, 1959 "5 Sheets-Sheet 4 FIEIE.

INVENTOR. ALBEPT W 7bA/D12EAU BY W ATTORNEY.

April 29, 1941. A. W. TONE5REAU 2,240,033

FILM PRINTING APPARATUS Filed Jan. 9, 1959 5 Sheets-Sheet 5 INVENTOR.

ALBERT W Ewan-40 ATTORNEY. V

Patented Apr. 29, 1941 FILM PRINTING APPARATUS Albert W. Tondreau, Hollywood, Calili, assignor to Warner Bros. Pictures, Inc., New York, N. Y., a

corporation of Delaware Application January 9, 1939, Serial No. 249,956

12 Claims.

This invention relates to apparatus for printing elongated films of the motion picture type and has particular reference to apparatus for contact printing the sound track of motion picture films in a continuous manner.

One object of the invention is to obtain an intimate contact between films being printed at the printing point.

Another object of the invention is to prevent relative slippage of films being printed while passing in contact past the printing point.

Another object of the invention is to utilize the adjacent edges of a pair of spaced rotatable film guiding members to limit the width of a sound track being printed.

Another object is to prevent variations of speed in a film drive from being transmitted to films being printed while they are passing the printing point.

Another object is to facilitate removal and replacement of the parts of a film printing apparatus,

Another object is to permit a printer mechanism to be quickly started and stopped.

The manner in which the above and other objects of the invention are accomplished may be readily understood on reference to the following specification read in conjunction with the accompanying drawings wherein:

Fig. 1 is a side elevational view of a contact printing apparatus embodying the present invention.

Fig. 2 is a rear elevational view, with parts in section, cf the printing apparatus.

Fig. 3 is a sectional plan view through the printing chamber and is taken along the line 3-3 of Fig. 6.

Fig. 4 is a sectional view through the pad unit and is taken along the line 4-4 of Fig. 6.

Fig. 5 is a sectional view taken along the line 5-5 of Fig. 4.

Fig. 6 is a sectional elevational view taken along the line 6-6 of Fig. 3.

Fig. 7 is a sectional view through one of the take-up reel drives and is taken along the line .'-I of Fig. 2.

Fig. 8 is a transverse sectional view illustrating the motor clutch and is taken along the line 8-8 of Fig. 2.

Fig. 9 is a sectional view through the drive for the printing drum unit and is taken along the line 99 of Fig. 2.

Referring in particular to Fig. 1, the developed negative film N, having a sound track thereon, is fed from a supply reel I0 and passes over a guide roller II, under a second guide roller I2 having edge guiding flanges thereon to guide the edges of the film, and thence passes in contact with a light sensitive positive film P onto a film feeding sprocket I3. Film N thence passes under a weighted roller I4, over a roller I5 having edge guiding flanges formed thereon, and thence passes over the periphery of a rotatable printing drum unit, generally indicated at I6, during which time the sound track of film N is printed onto the positive film P. From the drum unit I6, film N passes around a weighted roller ll having edge guiding flanges thereon, over film hold-back sprocket I8, over a guide roller I9 and onto a take-up reel 20.

The positive film? is drawn from a supply reel 22 and passes over a guide roller 23, under a second guide roller 24 having edge guiding flanges thereon, and thence in contact with the film N while passing over the sprocket I3. Film P, after passing over the sprocket I3 is separated from film N and is led in a sinuous path around spaced rollers 25, 26, 21 and 28, the roller 21 being weighted. Roller 28 has edge guiding flanges thereon to accurately position the film transversely. From roller 28 the film P again passes in contact with the film N while passing over the printing drum unit I6 during the printing operation and is thereafter led around a weighted roller 29. The film is then led in a sinuous path around a roller 30, and a roller 3| having edge guiding flanges thereon. The film P is then drawn over a film hold-back sprocket 32, around a guide roller 33 and is rolled on a takeup reel 34. The various sprockets l3, I8 and 32, the drum unit I6, and the take-up reels 20 and 34 are all driven from a single motor in a manner hereinafter described.

It should be noted that the width of the sprocket teeth 38 is less than that of the sprocket perforations in the films. Thus the films are guided laterally over the drum unit'by the respective edge guiding rollers I5, Ii, 28 and 29.

Referring to Figs. 3 and 6, the printing drum unit I6 comprises a sprocket member 36 integrally formed on a shaft 31 and having sprocket teeth 38 thereon adapted to engage the sprocket perforations along one side of the two films N and P while passing thereover. Sprocket 36 has a cylindrical flange 39 secured thereto by bolts 40 to support the picture portions of the films traveling thereover. The right hand end of -flange 39 (Fig. 3) is bevelled and is aligned with the edge of the sound track of film N directly forms a mask for preventing exposure of a portion of the picture portion of film P while printing the sound track thereon from film N.

The shaft 31 is journalled in a bearing member 4| fitted in a bore 42 provided in a cylindrical protuberance 43 integrally formed on the printer casing 44.

The edges of the films N and P adjacent the sound track portion thereof are supported by an annular, or ring shaped film guiding member 45 having an opening 45 extending therethrough. Member 45 is journalled in a ring shaped bearing member 41 securely fitted in a counter bore 43 provided in a sleeve member 49. Sleeve member 49 is removably fitted in the bore 42 and is secured therein by bolts 53 extending through lugs projecting from the cylindrical protuberance 43. Screws 50 are threaded in a circular flange 52 formed on the sleeve 49.

The film guiding surface 53 of ring 45 is of the same diameter as that of the flange 39 of sprocket member 35. The left hand edge of ring 45 is bevelled and is aligned with the left hand edge of the sound track to form a mask for limiting the width of the sound track. The ring 45 has a shoulder 54 formed thereon which engages one end of the bearing ring 41 to prevent longitudinal movement of ring 45 toward the sprocket member 35. An annular gear 55 is secured to the ring 45 by screws 56 on the opposite side of the ring 41 and has a shoulder formed thereon which engages the ring 41 toprevent longitudinal movement of the ring 45 while permitting rotation thereof.

The ring 45 is driven in synchronism with the sprocket member 35 by the train of gears 55, 51, 58 and 59. The gear 59 is secured to the sprocket member 36 by bolts 60 and dowel pins 6|, and is of the same pitch diameter as the annular gear 55. The gears 51 and 58, meshing with the gears 55 and 59, respectively, are secured on opposite ends of a stub shaft 62, retatably mounted in ball bearings 63 and 64 mounted in a bearing supporting member 65 (Fig. 6). Member 65 is pivoted at the upper end thereof on a pin 66 extending between brackets as at 61, projecting from the cylindrical protuberance 43. The lower end of member 65 is clamped in a position to mesh the gears 51 and 58 with their respective gears 55 and 59 by a locking screw 68 passing through member 55 and threaded in the cylindrical protuberance 43. A set screw 69 is threaded in member 55 and abuts the adjacent face of the protuberance 43 so as to permit adjustment of the member 65, and consequently the gears 51 and 58, to and from the respective gears 55 and 53 to correct for wear, etc, Gears 51 and 58 extend through an opening formed in the protuberance 43. Gear 51 also extends through an opening 1! formed in the sleeve 49 co-extensive with opening 10.

The printing light is obtained from a lamp 13 suitably mounted in an enclosed lamp house 14 which is formed integral with an end cover 15. Cover is secured to the flange 52 of sleeve 49 by screws 16 which extend through elongated slots 11 in flange 52 and are threaded in the end cover 15. Slots 11 are provided on opposite sides of flange 52 and extend parallel to each other permitting the end cover to be adjusted transversely in a horizontal direction. A lens tube 18 is mounted in a bore formed in the combined end cover 15 and lamp house 14, and is adapted to be locked in any adjusted position by a set screw 19. Lens tube 18 has mounted therein a condenser lens 38 and a slit member ill having a horizontally extending slit therein. A second lens tube 52, co-axial with the tube 18, is securely fitted in a sleeve 83 removably mounted in a bore formed in an end member 54 which is secured to the end cover 15 by screws 85. The lens tube 82 may be locked in different positions relative to the tube "ill by a set screw 85.

A prism 53 suitably mounted in a prism holder 89 is provided at the front of the lens tube 82 to deflect a beam of light passing through the tube 82 at right angles thereto and onto the films N and P at the center of their arcuate contact with the drum unit 15. The prism holder 83 has a bore therein fitted over the reduced forward end of the tube 82 and is adapted to be locked in different positions thereon by a set screw 95. A set of objective lenses Si is provided at the forward end of the tube 82 to focus the illuminated slit of member 81 onto the films N and P in the form of a fine horizontal slit of light. It has been found that when the beam of light impinging on the films is very narrow, on the order of .016 inch, the best results are obtained. In any event, the length of the slit in member 8! is such that the beam of light striking the films extends slightly over the adjacent ends of the sprocket and ring 45.

t will be noted the entire optical system, in-

cluding the lamp l3, lens tubes 13 and 82 and prism 88 are all carried by the end cover 15. Thus, the printing light beam may be accurately focused on the films N and P by loosening the screws 15 and moving the end cover 15 transversely until the beam is accurately focused, whereupon the cover l5 may be locked in place. This focusing feature as well as the general arrangement of the optical system and prism is disclosed and claimed in the co-pending application of Albert W. Tondreau, Serial No. 230,523, filed September 17, 193

When the optical system is to be removed for cleaning or repair, or whenever it is desired to gain access to the interior of the printing coinpartinent, the bearing member is move-d rearwardly, causing the gears 51 and 58 to be withdrawn from the opening it while the screws 55 are withdrawn, allowing the sleeve 49, carrying the ring 45 and entire optical system to he slid out of the bore 42. Thus, the original adjustment of the various elements of the optical system relative to each other and to the ring 45 need not be disturbed Furthermore, this provision insures accurate realignment of the optical system and ring 45 with the sprocket member 35 and other elements of the film driving system when the sleeve 45 is replaced in the bore 42. The bearing member airotatably supporting the sprocket member may likewise be removed from the bore 42 when the gear 53 is removed from mesh with the gear 59.

Referring now to Figs. 3, l, 5 and 6, the films N and P are urged into intimate contact with each other on the drum unit 16 by a pad and gate device generally indicated at 94. This device comprises a pad member pivotally mounted on a stud 35 secured in a boss 91 formed on the printer casing wall 64. A web guiding spool I96 is rotatably mounted by ball bearings [91 on a stub shaft 98 secured at one end thereof to a lug 99 extending from member 95 by a screw H30. A second web guiding spool I5! is rotatably mounted by ball bearings I02 on a stub shaft I03 supported at the top of the member 95. Shaft 1'03. has an enlarged circular shoulder portion I04 formed thereon and adapted to engage the sides of a lug I65 extending from the top of member 95. A rectangular bearing portion I36 is formed on shaft I63 to the rear of shoulder I04 and is adapted to be guided in a guideway IOI formed in the lug 65. Shaft I63 is adapted to be locked into different positions along-the guideway III! by ascrew I63 threaded in the bearing portion I66 and engaging a washer I09 which bridges the guideway I6! and engages the sides of lug I65. An adjusting screw IIO threaded in the lug I65 engages the under surface of the bearing portion I66 of shaft I63 topermit adjustment of the spool I6I toward and away from the spool I96. An endless fabric web H2 is looped over the spools I96 and IilI and is held from transverse movement on the spools byfianges II3 formed on the ends of each of the spools. The tautness of the web II2 may be varied by adjustment of screw I II). A guard H4 is secured to the mem-- ber 35 to protect the web II2 from injury.

Member 95 has a depending lug H5 formed thereon which is pivotally connected by means of a pin II6 to a plunger rod III, the lower end of which is fitted within a cylindrical sleeve-H8 having alug IIS extending thereon'and pivoted on a bolt I26 threaded in the casing wall 44' of the printer casing. A compression spring I2I is interposed between the sleeve I I8 and a shoulder I22 integrally formed on the plunger II! to urge the plunger II'I upwardly. Plunger III urges the gate member 95 in a clockwise direction to engage the web II2 against the films N and P on the sprocket 36 and ring 45 to hold the same in intimate contact during their passage past the printing light beam. A set screw I23 (Figs. 3 and 6) is threaded in the gate member 95 and abuts the protuberance 43 to limit the inward movement of the member 95. The innermost position of the memberSE may thus be adjusted by adjustment of screw I23. By drawing the member 95 outwardly away from the drum unit I6 into a position wherein the pin II6 passes across a line extending between the stub shaft 96 and the bolt I26, the member 95 will be urged into an open or threading position by the spring I2I.

It will be seen from the abov that by adjustment of the screws III] and I23 the arc of contact of the web II2, as well as the pressure produced thereby on the films N and P, may be varied as desired. Since a comparatively long arc of contact is obtainable between the web 2 and the films, it will be seen that an intimate engagement may be effected between the two films. Thus any air which may be lodged between the two films forming blisters or air pockets will be ironed out in advance of the printing point.

Referring to Fig. 6, the weighted roller I4 adapted to tension the negative film N between the sprocket I3 and drum unit I6 is rotatably mounted on a stub shaft I24 extending from a weighted arm i25 which is pivotally mounted on a stub shaft I26 extending from the printer casing wall 44 and forming a bearing for the guide roller I5. The weighted roller 21 for tensioning the positive film P intermediate the sprocket I3 and the drum unit I6 is similarly journalled on a stub shaft I21 extending from a weighted arm I28 which is pivotally mounted on a stub shaft I29 extending from the printer casing wall 44 and forming a bearing for the guide roller 28. The guide roller 28 is so positioned as to lead thefilm P into contact with the film N at an angle of approximately 3'. A

guide plate I36 suitably secured in the opening I3I formed in the cylindrical protuberance 43 lies parallel to the path of the film N extending,

between-the roller I5 and the drum unit I6 to l /2 apart.

guide the film N. A similar guide plate I32 is secured at the bottom of the opening I3I to guide the film N between the drum unit I6 and the lower weighted roller IT.

The weighted roller I! for tensioning the film N intermediate the drum unit I6 and the lower sprocket i6 is rotatably mounted on a stub shaft 233 extending from an arm I34 which is pivoted at I35'to the wall 3 3'.

The weighted roller 29 for tensioning the film P intermediate the drum unit I6 and the sprocket 32is journalled on a stub shaft I36 provided on the end of an arm I38 which is fixed on a shaft I36 journalled in a bearing formed in the wall 44. A weighted arm I is also secured on the shaft 33 to urge the roller 29 downwardly in a clockwise direction.

The rollers I T and 23 are so positioned that they lead the films N and P, respectively, from the drum unit it at a slight angle, preferably Also, the arms I34 and I38 rotatably supporting the rollers I1 and 29, respectively, are so positioned during the threading of the films that a line passing between the pivotal support of each arm and the shaft for its respective roller ":extends perpendicular to the path of the film The rollers I4 and I7 are so weighted that a drag of approximately one-half pound is applied to the driving edges of the sprocket teeth 38 of sprocket member 36 by the leading edges of the sprocket perforations of film N. To accomplish this, the arm R25 is preferably so weighted as to cause the roller I4 to exert approximately a one pound tension upwardly on the film N while the roller it and arm 934 are so weighted as to exert a one-half pound tension downwardly on film N. This distribution of weights is sufiicient to cause a good contact between the film N and the sprocket 36 and ring 45 while at the same time causing sumcient drag on the teeth 38 continually form a driving engagement between the teeth and the film. Further, this drag is insufficient to cause a strain on the film, especially tle sprocket perforations, by the sprocket teeth 3 1 Approximately a one-half pound drag "on the driving edges of the sprocket teeth 38 is also applied by the leading edges of the sprocket perfo- 1 rations of the film P. This is preferably accomplished by weighting the arm I28 to cause the I roller 21 to exert approximately a two and onealso aids in forming an intimate contact between film N and the surfaces of the sprocket member 36 and ring 45.

' Due to the fact that the films N and P are led in an are over the spaced members 36 and 45, the

tension applied thereto will create a lateral stiffness in the films while passing the printing point. Althoughthis tension applied to the films is considerable the drag upon the driving edges ofthe sprocket; teeth- 38 is only sufficient' to cause a driving effort to be exerted by these teeth on the leading edges of the sprocket perforations of the films as they pass over the drum unit, thereby reducing the tendency of the sprocket teeth to tear or wear the perforations of the films. Since the driving edges of the sprocket teeth are always in contact with the leading edges of the sprocket perforations of both films, the teeth will tend to prevent any relative slippage between the two films as they are being printed.

Due to the reduced drag on the sprocket teeth 38 by the films, the tendency for sprocket ripple or minute variations in speed occurring in rapid succession (caused by the various film perforations sliding unevenly off of the engaging surfaces of the respective sprocket teeth, or by microscopic ridges on the engaging surfaces of the sprocket teeth which catch the perforations) -will be materially reduced. The reduction of such sprocket ripple is very important, especially at a point closely adjacent the printing point, since the ripple tends to set up a chattering or uneven pull on the films and if permitted to travel along the film to the printing point, would cause an undesired sound record or distortion to be recorded on the film P.

The sprocket ripple caused by the passage of the heavily tensioned film P over the teeth of sprockets I3 and 32 is prevented to a large extent from being transmitted along the film P to the printing point by the provision of the sinuous paths in this film above and below the printing drum unit I6. These sinuous paths greatly increase the length of the film between the sprockets and printing point and consequently allow the cellulose film, due to its resiliency, to absorb these sprocket ripples. Furthermore, by causing the film to travel over and rotate the various rollers 25, 26, 21, and 3I a certain amount of the sprocket ripple is absorbed by the inertia of these rollers which tends to resist any small, quick variation in speed.

Referring to Figs. 2, and 9, the various sprockets and take-up reels are driven from a single motor I42 mounted at the rear of the printer casing 44. The drive shaft I43 of motor I42 is connected by means of a clutch generally indicated at I44 to a shaft I45 rotatably mounted in ball bearings I46 and I41 and having formed thereon a worm I48. Worm I48 meshes with a worm gear I49 secured on a stub shaft I50 which is journalled in bearings I5I and I52. Bearing I62 is formed in a bell member I53 suitably secured over an opening formed in the rear wall 44" of casing 44. The bearing I5I is formed in a cover plate i54 suitably secured over an opening formed in a gear compartment provided in the bell I53. A spider I55 is suitably secured on the inner end of the stub shaft I50 and has a pair of diametrically opposed fiber bushings I56 and I51 formed in bores extending therethrough. These bushings receive studs I58 and I59, respectively, secured on a gear I60 which is secured on the end of the drive shaft 31 which drives the sprocket member 36 of the printer drum unit I6.

The shaft I3 of the feed sprocket I3 has a gear I6I secured thereon, in the casing 44, which is driven from the gear I60 through an idler gear I62 which is journalled on a stub shaft I63 extending from casing wall 44. The sprocket shafts I8 and 32 of the sprockets I8 and 32, respectively, have gears I61 and I68, respectively, secured thereon which are also driven from the gear I60 through intermediate idler gears I64, I65 and I66. These various gears I60, I6I, I62, I64, I65, I66, I61 and I68 are of such diameters that the same peripheral velocity is applied to the various sprockets I 3, I8, 32 and 36.

Gear I68 meshes with an idler gear I69 journalled on a stub shaft I69 extending from the casing wall 44 to transmit motion to a take-up reel gear I10.

Referring to Fig. 7, the gear I10 is keyed on the hub of a disc member I1I journalled on a sleeve I12 fitted over a real shaft I13 on which is integrally formed the hub of reel 34. Shaft I13 is rotatably mounted in ball bearings I14 mounted in a sleeve I15 which is removably fitted in a bore formed in the front casing wall 44' of the printer casing 44. The disc member I1I forms part of a slip clutch generally indicated at I16 and engages a friction disc I11. A disc I18 engages the opposite side of the disc I11 and is slidably keyed at I19 to a hub I which is keyed to the reel shaft I13. A leaf spring I 8|, semicircular in shape, has an aperture I82 centrally located therein and fitted over the threaded end of shaft I13. Leaf spring IBI engages at the ends thereof diametrically opposed portions of the disc I18 to urge the same into frictional contact with disc I11 which, in turn, frictionally engages disc member I1I to obtain a non-positive driving connection between the gear I10 and the shaft I13. A nut I83 threaded on shaft I13 engages the leaf spring I8I and when moved along shaft I 13 varies the driving torque between the gear I19 and shaft I13.

The gear I61 (Fig. 2) meshes with an idler gear I84 journalled on a stub shaft I85 extending from the casing wall 44. Gear I84 meshes with a second take-up reel drive gear I85 for driving the take-up reel 34. A slip clutch (not shown) identical with that of I16 (Fig, 7) is provided to transmit rotation from the gear I85 t0 the reel 20.

Referring to Figs. 2 and 8, the clutch I44 comprises a drum I81 suitably secured on the motor shaft I43. Drum I81 has a cylindrical flange I88 formed thereon and adapted to be engaged on the inner surface thereof by a pair of diametrically opposed friction shoes I89 and I98.

Shoes I89 and I90 are pivotally connected at I8I and I92, respectively, to the ends of levers I93 and I94, respectively. Levers I93 and I94 are mounted intermediate their ends on pins 2(lI and 202, respectively, mounted on a disc member I98 which is secured on the shaft I45. The levers I93 and I94 are urged by springs I93 and I94 to cause their respective shoes I89 and I90 to engage the drum I81 to transmit rotation from the motor shaft I43 to the shaft I45 through the disc member I98. The rear ends of the levers I93 and I94 have semi-circular bearing surfaces formed thereon which ride on the periphery of a sleeve member 204 freely movable on the shaft I45. Sleeve 234 has a raised portion 205 formed at one end thereof and extending around the circumference thereof. A groove 206 is formed in the member 284, in which rides a pair of diametrically opposed pins 281 extending inwardly from the opposite ends of a yoke member 208. Yoke 208 is secured on a control shaft 209 journalled in a bearing 2I0 (Fig. 8) formed in the casing wall 44. Yoke 208 is moved by a control lever 2II (Fig. 1) provided at the front of the machine. A brake shoe 2I2 is supported from the yoke member 288 by a bracket H3 and is positioned so as to engage the periphery of the member I98 when the clutch I44 is disengaged.

When the handle 2II is thrown to the left (Fig. 2) the yoke member 208 causes the sleeve 204 to be moved to the right forcing the semicircular bearing surfaces of the levers I93 and I94 onto the periphery of the enlarged portion 285 of sleeve 298 againstthe action of the springs I93 and IQ i to disengage'the clutch shoes I89 and I90. Simultaneously the brake shoe 2I2 engages the periphery of member I98 to arrest the rotation of member W8 and the entire printing mechanism. This provision permits the entire printing mechanism to be stopped and started in a very short time.

While the ring 45 is preferably driven from the sprocket member through the train of gears 56, 51, 58 and 59, these gears may be omitted, in which case ring 45 would be driven through the films N and P due to the inward pressure applied thereto by the pad device 94 and by the weighted rollers l4, I1, 21 and 29.

In the event that it is desired to reduce the friction caused by the relatively large diameters of the engaging bearing surfaces of rings 45 and 4?, the optical assembly tubes I8 and 82 may be arranged co-axial of the sprocket shaft 31. In this case, the diameters of the bearing surfaces of rings 55 and 31 may be materially reduced.

Although I have described my invention in detail and therefore have utilized certain specific terms herein, it is to be understood that the present disclosure is illustrative rather than re- 1 strictive and that changes and modifications may be resorted to Without departing from the spirit of the following claims.

I claim:

1. In a film printing apparatus, the combination of a casing, means in said casing forming a cylindrical bearing, an annular film guiding member journalled in said bearing and adapted to guide a film over the periphery thereof, said member having an axial opening extending from one side thereof to the other, a portion of said film overhanging one side of said member, a light source on the opposite side of said member, and an optical unit extending through said opening and inside of said bearing for transmitting light from said light source to said overhanging portion of said film.

2. The combination according to claim 1 comprising means other'than said film for rotating said member.

3. In a film printing apparatus, the combination of a casing, a film drum adapted to guide a film over the periphery thereof with a portion of said film overhanging said drum, means rotatably supporting said drum in said casing, means in said casing forming a cylindrical bearing, an annular film guiding member having a sleeve journalled in said bearing and adapted to guide said overhanging portion of said film over the periphery thereof, said member being spaced from said drum, and means comprising light transmitting means extending through said sleeve for light impressing said film intermediate said member and said drum.

4. The combination according to claim 3 comprising means other than said film for driving said member and said drum in synchronism.

5. In a film printing apparatus, the combination of means forming a cylindrical bearing, an annular film guiding member journalled in said bearing and adapted to guide a film over the periphery thereof and in overhanging relation thereto, an annular gear on said member and concentric therewith, a drive gear meshing with said annular gear for rotating said member and said 'gear, and light transmitting means extending through said annular gear and said member for light impressing the overhanging portion of said film.

6. In a film printing apparatus, the combination: of a casing, means in said casing forming a cylindrical bearing, an annular film guiding member journalled in said bearing and adapted to guide a film over the periphery thereof in overhanging relation thereto, said member having a shoulder thereon engaging one end of said bearing, an annular gear member secured on said member, said gear member forming a shoulder engaging the opposite end of said bearing to prevent endwise movement of said film guiding member, a drive gear meshing with said gear member and adapted to rotate said member, and a light transmitting unit extending through said member for light impressing the overhanging portion of said film.

'7. In a film printing apparatus, a casing having a bore therein, a sleeve removably fitted in said bore, a sleeve bearing in said sleeve, an annular film guiding member journalled in said bearing and adapted to guide a film thereover, an optical assembly unit extending through said sleeve bearing and adapted to transmit light to said film, and means on said sleeve supporting said unit.

8. In a film printing apparatus, the combination of a casing having a bore therein, a sleeve removably fitted in said bore, a sleeve bearing in said sleeve, an annular film guiding member journalled in said bearing and adapted to guide a film thereover, an optical assembly unit extending through said sleeve bearing and adapted to transmit light to said film, a supporting member for said unit, and adjustable means for securing said supporting member in different positions on said sleeve to change the position of said unit relative to said film.

-9. In a film printing apparatus, the combination of a casing having a bore therein, a film drum adapted to guide a film over the periphery thereof with a portion of said film overhanging said drum, means rotatably supporting said drum in said bore, a sleeve removably fitted in said bore, a hollow bearing in said sleeve, an annular film guiding member journalled in said bearing and spaced'from said drum for guiding said overhanging portion of said film, an optical assembly unit extending through said bearing and adapted to transmit light to said film intermediate said drum and said member.

10. The combination according to claim 9 comprising means for rotating said drum and said member in synchronism.

'11. Film printing apparatus comprising a rotatable drum adapted to guide a pair of films in contact thereover in printing relation on said drum, an optical system adapted to project an optical slit from a light source, said optical system being arranged with the axis thereof substantially parallel with the axis of said drum, a light deflector for deflecting said optical slit to a focus adjacent the surface of said drum, a mount for said optical system, and means Whereby said mount may be adjusted transversely of the optical axis of said system to adjust said focus.

12. Film printing apparatus comprising a rotatable drum adapted to guide a pair of films in contact thereover in printing relation on said drum, an optical system adapted to project an optical slit from a light source, said optical systom being arranged with the axis thereof substantially parallel with the axis of said drum, a light deflector for deflecting said optical slit to a focus adjacent the surface of said drum, said optical system having an optical axis portion extending lengthwise of the axis of said drum and means for deflecting another portion thereof 

